The use of channeling agents, such as polyethylene glycol (PEG) for channeling moisture, oxygen, or other materials, through polymers, is known, and has been described in, for example U.S. Pat. Nos. 5,911,937, 6,080,350, 6,124,006, 6,130,263, 6,194,079, 6,214,255, 6,486,231 and 7,005,459, each of which is incorporated herein by reference as if fully set forth. Such channeling agents may be incorporated into packaging by way of a polymeric sleeve, insert, or package formed of the polymer itself. The polymeric material containing the channeling agent is further entrained with an active agent, for example, an absorbing or releasing material. The channeling agent forms channels between the interior of package and the active agent located interior to the polymer, to transmit a selected material, which may be, for example a material absorbed or released by the absorbing or releasing material.
Such polymers can be useful, for example, in packaging of pharmaceuticals, nutraceuticals, medical devices, foodstuffs, electronics and tobacco products. The entrained polymer, and as a result, some of the channeling agent incorporated therein, will contact the packaged material in these types of applications. As a result, the use of a channeling agent that does not migrate into the packaged product is desirable, so as to avoid contact with or possible consumption of the channeling agent by the consumer. Such a channeling agent may be, for example, a water insoluble polymer, so that contact with moisture in the product does not cause extraction of the channeling agent.